A multistage synthesis of 9-dimethylaminotetrahydrodicyclopentadiene (the Decane) is described by P. Wilder, Jr., Ch, F. Culberson, and G. T. youngblood in J. Am. Chem. Soc. 81, 655 to 658 (1959). Starting from a ketone (tricyclo[5.2.1.0.sup.2,6 ]decane-8(9)-one), the corresponding oxime is prepared by reaction with hydroxylamine. The oxime is reduced in two separate stages (first by means of PtO.sub.2 and H.sub.2 and then by means of sodium) to the corresponding amine (8(9)-aminotricyclo[5.2.1.0.sup.2,6 ]decane). The amine can be converted to the corresponding (9)-dimethylaminotetrahydrodicyclopentadiene (the Decane) by a mixture of aqueous formaldehyde and formic acid. The yield in the methylation stage is only 48% based on the primary amine employed, and the yield based on the overall preparation process is correspondingly lower.
WO 90/04567 describes a process for preparing N,N-dialkyl-8-aminotricyclo[5.2.1.0]decane (the Decane), starting from 8-ketotricyclo[5.2.1.0]decane (tricyclo[5.2.1.0.sup.2,6 ]decan-8(9)-one). In this process the ketone is reacted with a dialkylformamide in the presence of formic acid at temperatures of 160.degree. to 195.degree. C.; the reaction time is 10 to 50 hours. CO.sub.2 is formed in the reaction, and has to be removed continuously in order to avoid an undesirable rise in pressure.
The aforedescribed processes are not only technically extremely complex, but are also very time-consuming.